Long before A Great Big World‘s Ian Axel and Chad Vaccarino teamed up with Christina Aguilera on their latest single “Say Something,” they were making the rounds in small venues throughout New York. Axel met Vaccarino while both attended New York University and they began penning songs together. When Axel broke out as a solo artist, he and Vaccarino remained songwriting partners.

In 2012, the duo joined forces officially as A Great Big World and released a six-song EP, with a little help from fans via Kickstarter. Their single, “This Is The New Year,” which Axel had sang for years as a solo artist, was performed by the cast of Glee in 2013 and the band soon signed to Epic Records.

“Say Something” was officially released in September, but thanks to a feature on So You Think You Can Dance, Aguilera heard the song and asked if the band would re-record it with her. On Nov. 4, the new version was released and the band would go on to perform it with her on The Voice. Now comes the song’s video. Watch above.

A track written when both Axel and Vaccarino were going through heartbreak, the stripped-down video showcases this hurt. Vignettes of couples at various life stages only add to the emotion on the Christopher Sims-directed clip.

The experience of working with Aguilera is one A Great Big World are still pinching themselves about.

“We look at Christina as this icon who can say anything and make it sound amazing,” Axel told Billboard. “And here we are, just us and her in the studio, and she’s asking our opinions on what sounds good, and everything out of her mouth was sounding good! Who are we to give Christina Aguilera vocal advice?”

A Great Big World’s debut album, Is There Anybody Out There?, will be released Jan. 14.